1. Field of the Invention
The present invention generally relates to an engine control apparatus. More particularly, the present invention relates to an engine control apparatus for synchronizing a rotational speed of an engine to an input rotational speed of a transmission when a clutch is released and the transmission is shifted.
2. Background Information
In a vehicle equipped with a manual transmission, when a clutch of the vehicle is released in order to shift gears, the input rotational speed of the clutch changes depending on the rotational speed of the engine and the output rotational speed of the clutch, i.e., the input rotational speed of the transmission, changes depending on the vehicle speed and the gear position of the transmission. Consequently, a physical shock (“shift shock”) will occur if the clutch is connected with differing input and output rotational speeds after the gear position of the transmission has been changed.
In order to reduce the shift shock, it is necessary to synchronize the rotational speed of the engine with the input rotational speed of the transmission. In Japanese Laid-Open Patent Publication No. 58-200052, when the transmission is shifted, the shift shock is suppressed by executing a rotational speed synchronization control wherewith the rotational speed of the engine is controlled to a rotational speed corresponding to the gear position of the transmission. The rotational speed synchronization control is continued until the clutch connects. A clutch pedal switch is provided on the clutch pedal to detect whether the clutch is connected or released.
With Japanese Laid-Open Patent Publication No. 58-200052, the rotational speed synchronization control starts when the driver depresses the clutch pedal in order to shift gears. However, the rotational speed of the engine does not change right away because the rotational speed of the engine is controlled to a rotational speed corresponding to the gear position of the transmission prior to shifting (pre-shift gear position) until the driver operates the shift lever.
When upshifting, it is necessary to lower the rotational speed of the engine. If the rotational speed does not start to decrease soon after depressing the clutch, then it will take time to synchronize the rotational speed of the engine to a rotational speed corresponding to the gear position that the transmission will be in after shifting (post-shift gear position) and the drivability of the vehicle will decline.
In view of the above, it will be apparent to those skilled in the art from this disclosure that there exists a need for an improved engine control apparatus. This invention addresses this need in the art as well as other needs, which will become apparent to those skilled in the art from this disclosure.